Optical information recording media (optical discs) can be roughly classified, in accordance with the recording and reproducing manner thereof, into a ROM (read only memory) type, which is a type used only for reading, an R (recordable) type, which is a write-once type, and an RW (rewritable) type, which is a rewritable type. Among discs of these types, discs of the write-once type have a recording layer changeable by irradiation with a laser ray, and can be roughly classified mainly into the following in accordance with the recording manner thereof: a pitting type of making record marks, such as bores or pits, locally into the recording film; a phase-change type of changing the phase of the recording film; an interlayer reaction type of causing plural recording films to react with each other; and a type of decomposing a compound constituting the recording film.
As a recording film of the pitting type out of the above-mentioned types, disclosed is a recording film containing a low-melting-point metal such as Sn or Bi (for example, Patent Literature 1). This film makes use of a matter that pits are made in the recording layer by heating through a laser ray, so that the optical path length of a ray reflected thereon is changed, thereby making a change between the marks and the space region. As a recording film of the phase-change type, for example, a Te—O—Pd recording layer is disclosed (for example, Patent Literatures 2 and 3). By radiating a laser ray thereto, the recording film is changed in crystal structure to be changed in optical constant accordingly. Thus, record is made therein. As a recording film of the interlayer reaction type, disclosed is, for example, a recording film which is changed by a reaction between its two recording layers in contact with each other, for example, between In—O—(Ni, Mn, Mo) of its first recording layer and Se—Te—O—(Ti, Pd, Zr) of its second recording layer, so as to be changed in optical constant (for example, Patent Literature 4). As a recording film of the type of decomposing a compound constituting the recording film, a recording film is disclosed in which, for example, an oxide or nitride low in decomposition temperature is used (for example, Patent Literature 5). Record is made therein by heating the oxide or the like to be decomposed.